In addition to his work with Dr. Levy, Dr. Shillitoe will observe and participate in the research work of the other dental scientists at this school and will be expected to take full advantage of the resources of the other research departments in this Health Science Center, such as in the Medical School of the University of Texas, the Graduate School of Biomedical Sciences, and Baylor College of Medicine. Specific research objectives will be to extend the work and the findings of previous years in the general area of oral virology. The association between oral cancer and herpes simplex will continue to be investigated by the study of tissue sections from patients with oral cancer. As controls, tissues will be obtained from patients with leukoplakia with or without dysplasia, and from patients with mucous membrane disorders such as lichen planus. These will be stained with monoclonal antibodies to various proteins of herpes simplex virus using the sensitive avidin-biotin-peroxidase technique. If a particular protein of herpes simplex is found in the tissue then in vitro work will proceed to isolate and discover the function of this protein. An animal model will be used to investigate carcinogenesis by the herpes simplex virus. Since the data obtained so far in humans indicates that oral cancer has a complex etiology involving many factors, the animal model will be focussed on the known co-carcinogenic interaction of herpes simplex with various chemical compounds. The purpose of this work will be to determine which of the virus functions can be prevented by antiviral drugs or vaccination. The various experiments planned for this program consist of an integrated approach to the question of the role of herpes viruses in oral cancer.